Conventionally, there have been memory systems having a plurality of memory chips that are nonvolatile memories. The memory system stores data which a write command has requested to write into memory chips in a distributed manner. The data which a write command has requested to write is referred to as write data. If an error in the transfer of write data occurs, the memory system may be required to return to the state present immediately before starting to write that write data. Such writing is referred to as atomic write.